Cannabis DUI urine samples don't prove impairment or show the accused's current blood THC level.

If the police only took a urine sample they may not be able to prove in court that your THC blood concentration level was above the legal limit.

A urine sample alone is usually not enough evidence to prove impairment and convict someone of a cannabis DUI in Ontario. Since the police do not always take a blood sample, the Crown may try to rely on urinalysis testing only. We can use this lack of evidence in your favour.

The police and Crown will often use the words of their so-called "Drug Recognition Expert (DRE)" to prove impairment in cases where they do not have a blood sample. The reason why urine samples are unreliable in court is that cannabis can remain in a person’s body for upwards of 45 days. THC is a fat-soluble drug that stays in the body unlike alcohol. Cannabinoids will be found in urine samples long after the intoxicating effects of the drug have worn off.

A urine test only proves that the accused consumed cannabis at some point in the last two months (so what!). This doesn't mean they drove high. The time of consumption and degree of impairment remain unknown, yet urine samples are still used in cannabis impaired driving cases to show evidence of drug use. The Crown will look to combine the urine test with other evidence like incriminating admissions and the statements of the DRE and other officers.

The Crown needs more than just a positive THC urine test to prove you are guilty DUI by cannabis.

The purpose of the DRE is to collect more "evidence" via an interview and observational analysis of the accused. The DRE's job is to note any signs of drug impairment in give their opinion. Drug test are used such as:

1. Eye exams: Officers will note if the accused's pupils appear abnormal and whether they have droopy eye lids, jerking motions, an inability to focus on or track and follow a stimulus with their eyes smoothly.


2. Dividend attention tests: This includes the Romberg balance test, walking the line heal-to-toe, etc.


3. Interviews, statements, and other observations: Does the accused lose focus easily and seem to be searching for thoughts while talking? Are they slurring their speech?

Drug impairment tests are similar to tests for alcohol impairment. These are largely subjective opinions of the police “experts” and arresting officers. Subjextive tests can be very unreliable. Everyone reacts differently under stress particularly when facing potential criminal charges. Neurodivergent people may be wrongly described as impaired due to their atypical behaviour while sober.

DRE testing is far from being a "perfect science". Sober people can fail.

The accused may appear high, but not be. They may just have a medical condition or seem off because of something unrelated. Autistic people can be falsely accused of driving high because officers misinterpret their natural social cues.

Many things other than drugs can impact an accused's behaviour upon arrest. Language barriers and other communication problems can also negatively impact their ability to fully understand questions and instructions.

We use the Crown's inability to prove the accused's THC blood level and degree of impairment to win acquittals and get cannabis DUI charges dropped.

Since a urine sample does not prove impairment or blood THC concentration level, and DRE/police observations of impairment are subjective, most cannabis DUI cases are highly triable. We present this reasonable doubt to the Crown Attorney and ask them to withdraw/drop the charges (sometimes in exchange for an HTA offence like careless driving). If the Crown refuses to drop the charges, we set the case down for trial and present to the judge that the Crown can't prove their case.

If the judge agrees and finds reasonable doubt the accused will be found not guilty. Not having a blood THC test result works to the advantage of the accused. Daily or habitual users of marijuana will always have a positive urine sample whether they are currently impaired or not.

Cannabis impaired DUI charges are often far more difficult to prove in court than people realize (especially if no blood samples were taken).

Some accused wrongly equate a positive urinalysis with proof of impairment similar to a breathalyzer. The breathalyzer is far more conclusive (better evidence). The police make it seem like it is all the same, but a urine test does not show their current blood THC level. Cannabis DUI accused may wrongly believe the evidence against them is strong and plead guilty when they could have walked free had their case been challenged in court.

Even the minimum sentence for cannabis DUI in Canada is considered a criminal record (conviction). Cannabus DUI cases are not open and shut. The Crown often doesn't have a very good case. It may be possible to get the charges dropped or be acquitted at trial.

You don't have to jeopardize your future or waste thousands of dollars on excessive legal fees. We provide effective and affordable lawyer representation for those charged with impaired driving throughout all of Ontario, Canada.

Have a skilled criminal lawyer who focuses on defending DUI charges protect you and your future from the consequences of a criminal record.




Are you a lawyer? If you are defending a impaired driving related case and are looking for expert advice regarding possible defences, case strategies, and information release management call us at: 647-228-5969.

Please note: We do not accept legal aid certificate cases. All clients are handled on a private retainer only.

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